Method for creating lines of weakness in thread-reinforced structures

ABSTRACT

A laminated structure comprising at least one ply of cellulosic wadding with reinforcing threads secured thereto has a plurality of spaced lines of perforations separating discrete sheets of the laminated structure. Each line of perforations is defined by a series of spaced, discrete cuts spaced apart by uncut regions. The tensile strength of segments of reinforcing threads disposed in the uncut regions is substantially lower than the tensile strength of segments of reinforcing threads disposed outside of the uncut regions to thereby define lines of weakness along the lines of perforations. Method and apparatus for creating the above-described lines of weakness in the laminated structure by applying a crushing force in at least uncut regions to substantially weaken the segments of reinforcing threads disposed in the uncut regions.

United States Patent [191 Lewyckyj Sept. 17, .1974

[ METHOD FOR CREATING LINES OF WEAKNESS IN THREAD-REINFORCED STRUCTURES[75] Inventor: Roman Lewyckyj, Philadelphia, Pa.

[73] Assignee: Scott Paper Company, Philadelphia,

22 Filed: Dec. 29, 1972 [21] Appl. No.: 319,862

Related U.S. Application Data [62] Division of Ser. No. 91,240, Nov. 20,1970, Pat. No.

Primary Examiner-Andrew R. Juhasz Assistant ExaminerLeon GildenAttorney, Agent, or Firm-Martin L. Faigus; William J. Foley [57]ABSTRACT A laminated structure comprising at least one ply of cellulosicwadding with reinforcing threads secured thereto has a plurality ofspaced lines of perforations separating discrete sheets of the laminatedstructure. Each line of perforations is defined by a series of spaced,discrete cuts spaced apart by uncut regions. The tensile strength ofsegments of reinforcing threads disposed in the uncut regions issubstantially lower than the tensile strength of segments of reinforcingthreads disposed outside of the uncut regions to thereby define lines ofweakness along the lines of perforations. Method and apparatus forcreating the .above-described lines of weakness in the laminatedstructure by applying a crushing force in at least uncut regions tosubstantially weaken the segments of reinforcing threads disposed in theuncut regions.

11 Claims, 10 Drawing Figures PATENTEDSEPI 71974 SHEET 2 (IF 3' METHODFOR CREATING LINES OF WEAKNESS IN THREAD-REINFORCED STRUCTURES RELATEDAPPLICATIONS BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to a laminated structure comprising at least one plyof cellulosic wadding with reinforcing threads secured thereto andhaving at least one line of weakness therein, and to methods andapparatus for forming said lines of weakness. More specifically, thisinvention relates to a laminated structure comprising at least one plyof cellulosic wadding with reinforcing threads secured thereto, andhaving at least one line of weakness therein defined by a series ofspaced discrete cuts separated by uncut regions, wherein the tensilestrength of segments of the reinforcing threads disposed in the uncutregions is substantially lowered to permit easy separation of thelaminated structure along the lines of weakness; and to methods andapparatus for creating the lines of weakness.

DESCRIPTION OF THE PRIOR ART Substantial interest exists in developinglow cost, nonwoven base sheets having substantial strength anddurability to be utilized in replacing conventional higher cost textilematerials in manufacturing products such as towels, wiping materials,bibs, aprons, and many other products wherein disposability is a desiredfeature. scrim-reinforced paper laminates, as exemplified in US. Pat.No. 3,072,511, have been effectively utilized in disposable garments andin sanitary paper products, such as paper towels. Products such as papertowels are often packaged in continuous roll form with spaced lines ofperforations defining discrete sheets which are separable from the mainroll along said lines.

In conventional perforating methods, a line of perforations is formed bysimply cutting, or punching through an article at spaced intervals toform a line of discontinuous cuts defined by cut segments separated byuncut regions. When a threador scrim-reinforced article is perforated byconventional methods, the threads disposed in cut segments will be cutand the threads disposed in uncut regions will retain their strength andprovide an impediment to separation along the line of perforations. Inmany instances the position of reinforcing threads in an article is suchthat at least a few threads will coincide with uncut regions in thelines of perforations. In such instances, the impediment to separationalong the lines of perforations may result in a tearing of the body ofthe sheet to be separated. Also, application of a force to separate asheet from the main roll may result in an unwinding of the roll ratherthan the desired separation. When reinforcing-threads coincide withuncut regions it is now necessary to hold the roll against rotation withone hand while separating a sheet with the other hand. This means thatone must have both hands free for separating a sheet, which in manyinstances, is not the situation when a sheet is desired. In view of theabove-described deficiencies, new methods for forming lines of weaknessin threador scrim-reinforced articles are necessary. Applicant is notaware of any prior art techniques for forming lines of weakness in athreador scrimreinforced product such that threads coinciding with uncutregions between cut segments in lines of perforations do not present anyimpediment to separating the product along such lines.

SUMMARY OF THE INVENTION Applicant has discovered that applying acrushing force to a laminated product comprising reinforcing threadssecured to a layer of cellulosic wadding, in the region of a reinforcingthread, will substantially reduce the tensile strength of thereinforcing thread. Furthermore applicant has discovered that thecrushing force will not substantially affect the integrity of thecellulosic wadding. More specifically, applicant has discovered that acrushing force can be applied to substantially destroy the tensilestrength of the reinforcing threads without materially affecting thetensile strength of the layer of cellulosic wadding, i.e., the tensilestrength of the crushed wadding is substantially the same, or onlyslightly lower than that of the uncrushed wadding, and in certainpressure ranges, the tensile strength of the crushed wadding is actuallyincreased over that of the uncrushed wadding. Therefore, the crushing ofuncut regions disposed between cut segments of lines of perforationswill substantially reduce the tensile strength of any reinforcingthreads disposed in such uncut regions without substantially reducingthe tensile strength of the cellulosic wadding in such regions. If thetensile strength of the cellulosic wadding were also substantiallyreduced in the uncut regions,

individual sheets of a rolled product would tend to become separatedfrom the main roll under such low forces that the roll could virtuallyfall apart during normal handling operations. Also, the lines ofweakness would be so weak as to prevent the sheet which has been crushedand provided with lines of perforations to be rolled in a continuousoperation at a winding station.

The unique method for forming lines of weakness in a liminated structurecomprising a layer of cellulosic wadding with reinforcing threadssecured thereto resides in applying a crushing force in at least uncutregions interconnecting cut segments of lines of perforations forsubstantially reducing the tensile strength of any reinforcing threadsdisposed in said uncut regions without destroying the tensile strengthor integrity of the layer of cellulosic wedding. The crushing forcepreferably is applied to the laminated structure prior to the cuttingoperation at a crushing station which is separate from the cuttingstation. The crushing force is applied either in a continuous crushregion which is coextensive with the zone to be cut, or in spaced,narrow regions which are parallel to each other and which are disposedat an acute angle to the discontinuous cut line formed at the cuttingstation. The crushing anvil for forming the spaced, narrow crushed zoneshas a crushing surface separated into crushing segments by spacedserrations. The ends of each narrow zone overlap adjacent zones in aperpendicular direction to the line of perforations to insure that allreinforcing threads in the region of the lines of perforations,including those coinciding with cut sections, will be crushed.

If desired, the crushing force can be applied to the uncut regionssimultaneously with the cutting operation by utilizing a speciallydesigned cutting and crushing blade, or the crushing force can beapplied subsequent to the cutting operation at a separate crushingstation. As stated earlier, the crushing operation is preferablyperformed prior to forming the lines of perforations.

The unique laminated structure of this invention is comprised of atleast one layer of cellulosic wadding with reinforcing threads securedthereto. The laminated structure has at least one line of weakness, eachline of weakness being defined by a line of perforations comprising aseries'of spaced, discrete cuts separated by uncut regions whereinsegments of reinforcing threads cross the uncut regions and have asubstantially lower tensile strength than segments of the reinforcingthread disposed outside of the uncut regions. More specifically, in themost preferred embodiment of this invention, the tensile strength ofsegments of reinforcing threads disposed in the tab regions issubstantially destroyed, whereas the tensile strength of the paper layerin the tab region remains substantially unaffected by the crushingforce. The advantage of this construction has been explained earlier.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an isometric view of alaminated product with spaced lines of weakness;

FIG. 2 is a schematic representation of a continuous production line forforming lines of weakness in a laminated structure according to theteachings of this invention;

FIG. 2A is a view of a standard perforating blade taken along line 2A2Aof FIG. 2;

FIG. 3A is an isometric view of a crushing anvil utilized in practicingone form of the method of this invention;

FIG. 3B is an isometric view of a crushing anvil utilized in practicinga second form of the method of this invention;

FIG. 4A is a fragmentary view showing a portion of a laminated structurewith a line of perforations and a crushed region formed by utilizing theanvil shown in FIG. 3A;

FIG. 4B is a fragmentary view of the laminated structure having a lineof perforations and series of overlapping crushed regions formed thereinby utilizing the anvil shown in FIG. 38;

FIG. 5 is an isometric view ofa perforating blade utilized in a thirdform of the method of this invention;

FIG. 6 is a schematic representation of a method of forming lines ofweakness according to still another form of the method of thisinvention; and

FIG. 7 is a graph illustrating the results achieved by this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention relates tomethods for forming lines of weakness in scrimor thread-reinforcedlaminated products, such as towels, household wipers, and the like. Aroll ofa thread-reinforced laminated product 10 having spaced lines ofweakness 12 is shown in FIG. 1. The spaced lines of weakness 12 defineindividual sheets 14 which are separable from the main roll along suchlines of weakness.

The laminated product 10 has outer layers of cellulosic wadding 16, 18to which a reinforcing web 20 is adhesively secured. Each layer ofcellulosic wadding 16, 18 may be single ply or multiple ply, and thereinforcing web 20 may be in any suitable form; such as interwoventhreads or cross-laid threads, forming a scrim having lengthwise threads22 and transverse threads 24. Any suitable technique for securing thereinforcing web to the cellulosic wadding can be utilized. For exampleadhesive can be applied to the cellulosic wadding or reinforcing web 20according to any of the methods disclosed in US. Pat. No. 3,072,511, thedisclosure of which is hereby incorporated by reference. Preferably, thereinforcing web 20is passed through an adhesive bath prior to beingsandwiched between respective cellulosic wadding layers 16, 18, and theadhesive on the reinforcing web adheres the cellulosic wadding plies andthe reinforcing web together.

Each line of weakness 12 is comprised of a line of perforations in theform of a plurality of discrete slit or cut segments 26 separated byuncut regions 28. A plurality of punched openings can be utilizedinstead of the cuts or slits. The term cut as used in this applicationis intended to encompass cuts, slits, punched openings, and the like,wherein the laminated structure is severed in discrete sections.

The reinforcing web 20 may be comprised of any thread or yarn having astrength which is substantially reduced, or destroyed upon theapplication of crushing forces thereto. The method of this invention hasbeen successfully employed with laminated products having reinforcingwebs constructed of rayon threads (300 denier), cotton threads (40/2),glass threads coated with plastisol (344 denier), polyester threads (110denier) and polypropylene threads. Laminated products having reinforcingwebs made of threads other than those enumerated above also can beutilized. These threads are well within the purview of those skilled inthe art, knowing that the critical criteria for selecting the thread isthat it be susceptible of physical degradation under crushing forces,such as compressive forces.

The outer layers of cellulosic wadding are preferably made from woodpulp fibers; however, it is contemplated that longer textile fibers canbe added to the wadding to increase its strength. The outer layers 16,18 must be susceptible of withstanding compressive loads withoutexcessive loss of tensile strength, and cellulosic wadding plies madefrom 100 percent wood pulp fibers meet this criteria.

In a continuous production line process some lengthwise threads 22 willcorrespond with uncut regions 28 of each line of weakness 12. The methodof this invention involves applying a crushing force in at least theuncut region of the lines of perforation to substantially reduce thetensile strength of the reinforcing threads in such regions. The amountof crushing load required to weaken the reinforcing threads will dependon the type of threads being used. It is desirable to apply the lowestforce possible for weakening, or substantially destroying the tensilestrength of the reinforcing threads to avoid excessive wear of thecrushing tools. In addition, excessively high pressures produce aglassine appearance in the product, which in most cases will beunacceptable to a consumer.

A schematic representation of a production line for perforating athread-laminated structure 10 according to a first form of the method ofthis invention is shown in FIG. 2. The roll of a scrimorthread-laminated product is fed from an unwind station 30 through acrushing station 32, a cutting station 34 and then to a rewind station36. A registration control unit 38 is disposed between the crushingstation 32 and cutting station 34, and is provided with a roll 40 whichis adjustable into fixed positions in the directions indicated by arrow42. This roll 40 is adjusted to control the length of travel of thelaminated product 10 between the crushing station 32 and the cuttingstation 34 to assure that the cutting operation takes placesubstantially in the same region as the crushing operation. The crushedsegments of the threads do not have to be in exact alignment with thelines of weakness 12; however, they should be reasonably close to assurethat the individual sheets 14 can be separated along substantiallystraight lines. The uncut regions 28 of the lines of perforations areintended to include those regions which are in exact alignment with cutsegments 26, and also those regions which are reasonably close to thelines of perforations as indicated in the preceding sentence.

The crushing station 32 is comprised ofa lower anvil support roll 44having a crushing anvil 46 connected thereto. The upper crushing surfaceof the anvil 46 cooperates with the surface of an upper crushing roll 48to provide a crushingforce to the laminated product 10 passingtherebetween. The crushing roll 48 is skewed approximately 2-5: degreesrelative to the lower roll 44. The skewed arrangement causes thecrushing surface of the anvil 46 to engage the periphery of the uppercrushing roll 48 progressively to thereby prevent excessive jarring ofthe equipment.

Referring to FIG. 3A, the crushing surface 461: of the anvil 46 is acontinuous, substantially planar surface. This continuous surface 46acooperates with the surface of the upper roll 48 to form a continuouscompressed region 50 (FIG. 4A) extending transversely across thelaminated product 10. Whenever the compressed region coincides with areinforcing thread 22, the thread will be crushed as shown at 22a inFIG. 4A. The laminated product is then fed through the registrationcontrol unit 38 to the cutting station 34.

The cutting station 34 is comprised of a lower carrier roll 52 having aflexible cutting blade 54 mounted therein. The flexible cutting blade 54is mounted to pass in interference with an anvil 56, which is firmlymounted in a stationary anvil holder 58, to engage and cut the laminatedproduct 10 passing therebetween. The anvil holder 58 and the anvil 56mounted therein are skewed relative to the axis of lower carrier roll 52to cause the cutting blade 54 to engage the anvil 56 progressively tothereby prevent excessive jarring of the equipment. The perforating orcutting blade 54 is I of conventional design and is provided with acutting edge which is interrupted by axially spaced grooves 59 to definediscrete cutting edge sections 54a (FIG. 2A). These cutting edgesegments 54a cooperate with the edge of anvil 56 to form discrete cutsegments 26 (FIGS. I and 4A). The laminated product 10 with lines ofweakness 12 formed therein is then wound into a continuous roll asrewind station 36.

Referring to FIG. 4A, the lengthwise threads 22 are all crushed in thecontinuous compressed region 50. Therefore, the lengthwise threads 22which cross uncut regions 28 will be substantially weakened and will nothinder or interfere with the separation of individual sheets 14 from themain roll of the laminated product 10.

In a second preferred embodiment of this invention, the crushing anvil47 shown in FIG. 3B, is utilized in lieu of the crushing anvil 46 shownin FIG. 3A. The crushing anvil 47 differs from crushing anvil 46 in thatit is provided with a serrated crushing surface to define discretecrushing surface segments 49. The serrations are disposed at an angle of45 to the long axis of the anvil to define planar crushing surfacesegments 49 disposed at 45 to the long axis of the anvil (which axisextends in the transverse direction of the laminated product 10). Thearea of the laminated product 10 which is compressed by the crushinganvil 47 is approximately one-half of the area which is compressed bythe crushing anvil 46. By reducing the area which is compressed, thecrushing force can also be reduced by approximately one-half (thecrushing pressure remaining substantially the same). The crushingsegment 49 of anvil 47 crush the laminated product in narrow, compressedregions 60 which are disposed at an angle of 45to the perforated lineand overlap one another in a perpendicular direction to said line toassure that all lengthwise threads 22 are crushed at or near the linedefined by cut segments 26 (FIG. 4B). Although all lengthwise threadsare crushed, the crushing of lengthwise threads 1 which are also cut bycut segments 26, does not provide any useful function.

In both the first and second embodiments of this invention, the distanceat the nip between rolls at the crushing station and the distance at thenip between the cutting blade and anvil can be varied to accommodatelaminated structures of different thickness. Since the cutting andcrushing stations are separate, the distance at the nips of bothstations can be adjusted independently of each other. Therefore, thesame cutting and crushing blades and anvils can be utilized withlaminated products of different thickness.

In a third preferred embodiment of this invention only those lengthwisethreads 22 which coincide with uncut regions 28 along the lines ofweakness are crushed. In this embodiment a separate crushing station andregistration control unit are not utilized. Conventional perforatingequipment is utilized with the exception that the conventionalperforating blade 54 is replaced by a unique cutting and crushing blade62 (FIG. 5). The cutting and crushing blade 62 is provided with acutting edge interrupted by notches 64 to define spaced cutting sections66. The notches 64 are provided with flat crushing surfaces 68, whichcooperate with the edge of the anvil 56 (FIG. 2) for crushing regions ofthe laminated product passing therebetween. The cutting and crushingblades 62 differs from the conventional perforating blade in that thenotches 64 are substantially more shallow than the notches of theconventional perforating blade. The specific depthof the notches willdepend upon the thickness of the laminated product being perforated;however, in all instances, the depth tolerance requirement is extremelyclose, and under normal mill conditions these tolerance requirements maybe difficult to maintain. In this embodiment of the invention theportions of the laminated product 10 coinciding with the cuttingsegments 66 are cut, and the portions coinciding with the notches 64 arecrushed. Therefore, the crushing force is only applied to threads whichare not cut. In this embodiment of the invention different blades mustbe used for forming lines of weakness in products of differentthickness.

A fourth preferred embodiment of this invention is schematically shownin FIG. 6. In this embodiment of the invention a fixed anvil holder 70is provided for mounting a notched anvil 72 and an unnotched anvil 74.The anvils 72 and 74 are held in palce by a screw 75. The notched anvil72 is notched in substantially the same manner as the perforating blade54 shown in FIG. 2A to define spaced edges which will cooperate with aknife edge of resilient unnotched cutting blade 76 to form the spacedcut segments 26 of the perforated line 12 (FIGS. 1, 4A). The unnotchedanvil 74 has a rounded crushing edge 78 which is spaced upwardly fromthe spaced edge segments of notched anvil 72. The rounded crushing edges78 cooperates with the resilient blade 76, which is spaced a distance d(FIG. 6) therefrom, for crushing the laminated product 10 across itsentire transverse dimension. The resilient blade is held in a lowercarrier roll 80 by ajaw element 82 and is spaced from the roundedcrushing edge 78 to prevent cutting of the laminated product 10 as it iscarscrim was a 4 X 6, staple rayon, leno-woven web sold commercially byChickopee Mills. The reinforcing scrim was first passed through anadhesive comprising latex (L9286 Uniroyal Naugatuck), and then adheredbetween the outer cellulosic wadding layers. Samples of one inch widthand four inch length were placed between a hardened anvil and hardenedsteel plate such that the lengthwise threads 22 were crushed. Severalsamples were crushed at various pressures ranging from 750 psi to100,000 psi. The samples were then cut with a perforating blade havingcutting segments having a length of 0.128 inches, separated by notcheshaving a length of approximately 0.027 inches to thereby form a line ofperforations having cut segments separated by uncut, crushed regions.The crushed and cut samples were then separated into two groups; onegroup having no lengthwise reinforcing threads in the uncut regions, andthe other group having one reinforcing thread extending through only oneuncut region. These samples were then tested to determine the forcerequired to separate each sample along the line of perforations. Theresults of this test are reported in tabular form below and in the graphshown in FIG. 7.

One Thread in Tab Region of One Inch Wide Sam le Kverage lenstle NoThreads in Tab Region of One Inch Wide Sam le Average Tensile riedtogether with the edge of the resilient blade 76 past the unnotchedanvil 74. The laminated product 10 is fed past the unnotched and notchedanvils at the same speed as the lower carrier roll 80 respectively. Aclearance 82 is provided adjacent blade 76 to permit said blade toresiliently deflect past the notched anvil. In utilizing the deviceshown schematically in FIG. 6, the laminated product 10 is first crushedalong substantially its entire transverse dimension by the intersectionof blade 76 and anvil 74 to crush all lengthwise threads 22 extendingthereacross. The laminated product is then cut in discrete segments 26by the interaction of the resilient blade 76 and notched anvil 72. Thismethod of forming transverse lines of weakness issubstantially the sameas the first method utilizing the production line of FIG. 2 with thecrushing anvil 46 (FIG. 3A).

The following example is given by way of illustration only, and is notintended to limit the scope of this invention. A laminated product 10having outer cellulosic wadding layers with a scrim reinforcing materialadhesively bonded therebetween was provided. Each outer layer ofcellulosic wadding consisted of two plies, and each ply had a basisweight of approximately 10.5 pounds per ream of 2,880 square feet. Thereinforcing The samples which did not have any reinforcing threadsextending through uncut regions gave a force reading of the strengthalong the lines of perforations of the four plies of cellulosic wadding.Since all reinforcing threads were cut, they did not have any effect onthe force required to separate the sample at the lines of P i9n$.-.

The results clearly indicate that for the product tested, a pressure ofapproximately 2,000 psi substantially weakens, or virtually destroys allof the strength of the reinforcing thread extending through an uncutregion without weakening the cellulosic wadding layers. This result isindicated by the following:

I. the tensile strength of the laminated product having no reinforcingthread in the uncut regions, is substantially the same as the tensilestrength of the laminated product having one thread extending in theuncut region which has been crushed; and

2. the force required to separate an uncrushed perforated sample havingno threads extending through the uncut regions is substantially the sameas'that required to separate the samples having no threads in the uncutregions and subjected to the entire range of crushing pressures of from750 psi to l00,000 psi.

Therefore, by the method of this invention, reinforcing threads=whichcoincide with the uncut regions in a line of perforations are crushedand their tensile properties substantially weakened, or virtuallydestroyed to prevent any hindrance to the separating of individualsheets from a laminated roll product. Furthermore, the tensile strengthof the cellulosic wadding layers are virtually unaffected by theapplication of crushing pressure.

What is claimed is:

l. A method for creating at least one line of weakness in a laminatedstructure having reinforcing threads secured to a substrate layer, saidlines of weakness each including a discontinuous cut line extendingthrough the laminated structure and spaced regions between the cuts inwhich the substrate layer is uncut, said reinforcing threads crossingsaid lines of weakness and having a tensile strength which issubstantially reduced by crushing forces of a magnitude which leavessubstantially unreduced the tensile strength of the substrate layer,said method including the following sequential steps:

A. applying a crushing force to said laminated structure in at leaseregions corresponding to the spaced regions of a line of weakness and ofa magnitude for substantially reducing the tensile strength of thereinforcing threads disposed in said spaced regions withoutsubstantially reducing the tensile strength of said substrate layer; and

B. cutting said laminated structure at spaced intervals to form saiddiscontinuous cut line.

2. A method according to claim 1, wherein the crushing force is of amagnitude for substantially destroying the tensile strength of thereinforcing threads disposed in said uncut regions.

3. The method according to claim 1, wherein the substrate layer iscomprised of at least one ply of cellulosic wadding.

4. The method according to claim 1, wherein said laminated structure iscrushed in a continuous compressed region whereby all reinforcingthreads in said compressed region are crushed.

5. The method according to claim I, wherein said laminated structure iscrushed in spaced, narrow regions which are substantially parallel toeach other and which are disposed at an acute angle to the direction ofthe discontinuous cut line for assuring that all reinforcing threads insaid uncut regions are crushed.

6. The method according to claim 5, wherein said laminated structure iscrushed such that portions of ad- 5 jacent, narrow regions overlap eachother in a perpendicular direction to said discontinuous line.

7. A method for creating at least one line of weakness in a laminatedstructure having reinforcing threads disposed between substrate layers,and lines of weakness each including a discontinuous out line extendingthrough the laminated structure and spaced regions between cuts in whichsaid substrate layers are uncut, said reinforcing threads crossing saidlines of weakness and having a tensile strength which is substantiallyreduced by crushing forces, said method including the following stepsperformed in either order or simultaneously:

A. applying a crushing force to said laminated structure in at leastregions corresponding to the spaced regions of a line of weaknesswithout cutting said substrate layers, said crushing force being of amagnitude for reducing the tensile strength of the reinforcing threadsdisposed in said spaced regions; and

B. cutting through said laminated structure at spaced intervals to formsaid discontinuous cut line.

8. The method according to claim 7 wherein the crushing force is of amagnitude for substantially destroying the tensile strength of thereinforcing threads disposed in said uncut regions.

9. The method according to claim 7, wherein said laminated structure iscrushed in a continuous compressed region extending between said spacedmarginal edges for crushing all reinforcing threads in said compressedregion.

10. The method according to claim 7, wherein said laminated structure iscrushed in spaced, narrow regions which are substantially parallel toeach other and disposed at an acute angle to the discontinuous cut linefor assuring that all reinforcing threads in uncut regions are crushed.

1]. The method according to claim 10, wherein said laminated structureis crushed such that portions of adjacent narrow regions overlap eachother in a perpendicular direction to said discontinuous line.

UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION Pa'tentNo. 5,754Dated September 17, 1974 in mfl Roman Lewyckyj It is certified thaterror appears in the above-identified patent afid that said LettersPatent are hereby corrected as shown below:

Column 2, line 45, change "liminated" to laminated. Column 2, line 52,change "wedding" to wadding-. Column 5, line 39, change "whenever" to--wherever-. Colunm 5, line 62, change "as" to -at-.

Column 7, line 8, change "palce" to place Column 7, line 17, change"edges' to edge-'.

Column 7, line 51, change "intersection" to interaction Signed andSealed this Twelfth Day of October 1976 [SEAL] Attest:

RUTH C. MASON I C. MARSHALL DANN Arresting Officer CommissionerofPatenIs and Trademarks

1. A method for creating at least one line of weakness in a laminatedstructure having reinforcing threads secured to a substrate layer, saidlines of weakness each including a discontinuous cut line extendingthrough the laminated structure and spaced regions between the cuts inwhich the substrate layer is uncut, said reinforcing threads crossingsaid lines of weakness and having a tensile strength which issubstantially reduced by crushing forces of a magnitude which leavessubstantially unreduced the tensile strength of the substrate layer,said method including the following sequential steps: A. applying acrushing force to said laminated structure in at lease regionscorresponding to the spaced regions of a line of weakness and of amagnitude for substantially reducing the tensile strength of thereinforcing threads disposed in said spaced regions withoutsubstantially reducing the tensile strength of said substrate layer; andB. cutting said laminated structure at spaced intervals to form saiddiscontinuous cut line.
 2. A method according to claim 1, wherein thecrushing force is of a magnitude for substantially destroying thetensile strength of the reinforcing threads disposed in said uncutregions.
 3. The method according to claim 1, wherein the substrate layeris comprised of at least one ply of cellulosic wadding.
 4. The methodaccording to claim 1, wherein said laminated structure is crushed in acontinuous compressed region whereby all reinforcing threads in saidcompressed region are crushed.
 5. The method according to claim 1,wherein said laminated structure is crushed in spaced, narrow regionswhich are substantially parallel to each other and which are disposed atan acute angle to the direction of the discontinuous cut line forassuring that all reinforcing threads in said uncut regions are crushed.6. The method according to claim 5, wherein said laminated structure iscrushed such that portions of adjacent, narrow regions overlap eachother in a perpendicular direction to said discontinuous line.
 7. Amethod for creating at least one line of weakness in a laminatedstructure having reinforcing threads disposed between substrate layers,and lines of weakness each including a discontinuous cut line extendingthrough the laminated structure and spaced regions between cuts in whichsaid substrate layers are uncut, said reinforcing threads crossing saidlines of weakness and having a tensile strength which is substantiallyreduced by crushing forces, said method including the following stepsperformed in either order or simultaneously: A. applying a crushingforce to said laminated structure in at least regions corresponding tothe spaced regions of a line of weakness without cutting said substratelayers, said crushing force being of a magnitude for reducing thetensile strength of the reinforcing threads disposed in said spacedregions; and B. cutting through said laminated structure at spacedintervals to form said discontinuous cut line.
 8. The method accordingto claim 7 wherein the crushing force is of a magnitude forsubstantially destroying the tensile strength of the reinforcing threadsdisposed in said uncut regions.
 9. The method according to claim 7,wherein said laminated structure is crushed in a continuous compressedregion extending between said spaced marginal edges for crushing allreinforcing threads in said compressed region.
 10. The method accordingto claim 7, wherein said laminated structure is crushed in spaced,narrow regions which are substantially parallel to each other anddisposed at an acute angle to the discontinuous cut line for assuringthat all reinforcing threads in uncut regions are crushed.
 11. Themethod according to claim 10, wherein said laminated structure iscrushed such that portions of adjacEnt narrow regions overlap each otherin a perpendicular direction to said discontinuous line.